There have been developed a wide variety of spermicide releasing devices for placement in the vagina for providing an effective level of spermicide within the vagina, such as described in an article by F. G. Burton, et al in CONTRACEPTION 17, pages 221-230, 1978, entitled "Fabrication and Testing of Vaginal Contraceptive Devices Designed for Release of Pre-Specified Dose Levels of Steroids", and U.S. Pat. No. 3,545,439 (the disclosure of which is hereby incorporated by reference herein). There also have been a wide variety of devices used for barrier methods of contraception, such as conventional diaphragms. While most of such devices are generally effective, there are a number of drawbacks associated with each.
Conventional barrier diaphragms have not been satisfactory for large fractions of the population because of the need to insert the barrier diaphragm, coated with a spermicidal formulation, within a few hours of coitus, the need to add additional spermicide if coitus is repeated, the need to remove the diaphragm after usage due to build up of unacceptable odors and/or the discomfort of the occlusive fit within the vagina, and the general unacceptability surrounding the "messiness" of the insertion, removal, and washing procedure for re-use. While vaginal rings releasing spermicide overcome some of the above-mentioned drawbacks associated with barrier diaphragms, in most instances they have not been demonstrated to be entirely effective in preventing conception.
According to the present invention, a contraceptive device is provided which overcomes most of the drawbacks associated with conventional barrier diaphragms and vaginal rings. The device according to the invention comprises a torus of biocompatible material sized to fit in a vagina, and has means formed therewith for providing a primary barrier preventing direct ejaculation into the cervix while allowing fluid drainage from the cervix. The device is designed to be disposable after one use (one menstrual period), is readily insertable, and can be constructed to allow release (e.g., diffusion) of spermicide therefrom at an effective level in the area between the device and the cervix to kill any sperm that pass the primary barrier. The device may be constructed so that the spermicide is more readily releasable through the inner peripheral surface thereof than through the outer peripheral surface thereof.
The device according to the present invention may be worn from the last of menses until the start of the next menstrual period. There is no "messiness" associated therewith since the spermicide is contained internally. The device may be discarded after one use, being relatively inexpensive to fabricate. While providing an effective barrier preventing direct ejaculation into the cervix, it allows fluid drainage in the opposite direction so that odors are minimized. The spermicide can be released in combination with a surfactant and/or foaming agent, and it permits complete mixing and spreading in the adjacent area so as to maintain a desired spermicidal concentration.
It is the primary object of the present invention to provide an effective, readily utilizable contraceptive device, and method of preventing conception utilizing same. This and other objects of the invention will become clear from an inspection of the detailed description of the invention and from the appended claims.